Q
Which statement is true regarding the use of 'Undefined'?

Answer & Solution

Answer: Option B
Solution:
Using 'Undefined' to represent missing or uninitialized values is discouraged as it can lead to unexpected behavior and is often considered a mistake in programming.
Related Questions on Average

How do you assign a variable to have a value of 'Null'?

A). Using the assignment operator =.

B). Using the null keyword.

C). Using the undefined keyword.

D). Using the void operator.

Which statement best describes the relationship between 'Undefined' and 'Null' in JavaScript?

A). Undefined and Null are interchangeable and can be used interchangeably in code.

B). Undefined and Null are distinct values representing different states in JavaScript.

C). Undefined is a subset of Null, encompassing all possible values of Null.

D). Null is a subset of Undefined, encompassing all possible values of Undefined.

Which of the following is a valid use case for 'Null' in JavaScript?

A). Storing default values in variables.

B). Clearing or resetting object references.

C). Assigning placeholders in arrays.

D). Checking if a variable exists.

Which of the following is an example of using 'Null' in JavaScript?

A). let user = null;

B). let user = undefined;

C). let user;

D). let user = '';

What is the result of the expression typeof undefinedVariable if undefinedVariable is not declared?

A). object

B). function

C). undefined

D). null

How is 'Null' different from 'Undefined'?

A). Null represents variables that have been initialized but not declared.

B). Null represents an intentional absence of value or object reference.

C). Null is never used in programming.

D). Null is a substitute for 'Undefined'.

What does the expression typeof null return in JavaScript?

A). null

B). object

C). undefined

D). function

What does the expression null == undefined return in JavaScript?

A). 1

B). 0

C). undefined

D). null

Which of the following scenarios is a common cause of variables having an 'Undefined' value?

A). When variables are explicitly set to 'Undefined'.

B). When variables are declared but not initialized.

C). When variables are intentionally set to 'Null'.

D). When variables are assigned default values.

What is the difference between 'Undefined' and 'Null' in JavaScript?

A). Undefined is a value, while Null is an absence of value.

B). Undefined is an absence of value, while Null is a value.

C). Undefined is never intentional, while Null is always intentional.

D). Undefined is always intentional, while Null is never intentional.